The present invention relates to a display board type switching device being operated by pressing switching displays positioned on a flexible display board of the device.
In general in a vehicle like an automobile, when operating under load like the wiper or the heater, the driver may operate individual switches by identifying the proper switch by means of a simplified symbol or notation provided thereon.
In order to give an easy identification of the switches and to improve the switching, a display type switch having a flexible board illustrating respective vehicle portions had been proposed.
One such proposal is to arrange a flexible display board having a picture of vehicle portions and an insulating sheet at the rear side thereof and portions in the insulating sheet corresponding to the desired switching position are cut and pressure sensitive conducting rubber members are placed in the cut portions so that by depressing the said switching position of the display board a corresponding pressure sensitive conducting rubber member is pressed, which becomes conductive to operate the desired load.
In such a display type switching device, the pressure sensitive conducting rubber members are located in the recesses of the insulating sheet at corresponding switching positions. If there is deviation among the size of the pressure sensitive conducting rubber members, various problems may be caused. When such a member is larger than a predetermined size, the member may be bent when it is inserted in the corresponding recess or cut portion and by lateral pressure applied thereon it is pressed towards top or bottom direction so that a small depression force causes conduction of the member and misoperation may result.
A further proposal had been made to provide clearances between the conducting body or electrode and the pressure sensitive conducting rubber member. But if the rubber member is too small and not closely fit in the cut portion, the member may shift in position due to the vibration of the vehicle during running to cause incomplete conduction.